One-component diazotype lightsensitive material

ABSTRACT

ONE-COMPONENT DIAZOTYPE LIGHT-SENSITIVE MATERIAL CONTAINING A CONDENSATION PRODUCT MADE FROM NAPHTHALENESULFONATE OR ALKYLNAPHTHALENESULFONATE AND FORMALDEHYDE AS A STABILIZER IN A PRECOAT LAYER ON A SUPPORTING SHEET, SAID MATERIAL HAVING GOOD STABILITY.

United States Patent Oifice 3,728,122 ONE-COMPONENT DIAZOTYPE LIGHT- SENSITIVE MATERIAL Shigeaki Yoshida, Yokohama, Shuhei Shiraishi, Fujisawa,

and Fumio Yuki, Tokyo, Japan, assignors to Ricoh Co., Ltd., Tokyo, Japan No Drawing. Filed Dec. 16, 1970, Ser. No. 98,932

Claims priority, application Japan, Dec. 17, 1969, 44/ 100,878 Int. Cl. G03c N60 US. Cl. 96-75 Claims ABSTRACT OF THE DISCLOSURE One-component diazotype light-sensitive material containing a condensation product made from naphthalenesulfonate or alkylnaphthalenesulfonate and formaldehyde as a stabilizer in a precoat layer on a supporting sheet, said material having good stability.

BACKGROUND OF THE INVENTION One-component diazotype light-sensitive material commonly comprises a supporting sheet having, on a surface thereof, a light-sensitive layer containing a stabilized lightsensitive diazonium compound which couples with an azo coupling component in an alkaline medium to form a visible azo dyestuif. Diazonium compounds as a general rule are not stable at higher temperatures. Normally those compounds having the highest sensitivity have the lowest stability with increasing temperature and humidity. Thus, the diazonium compounds having the better sensitivity because they react readily with the azo coupling component most readily decompose at higher temperatures and humidity. Acid stabilizers are often employed to alleviate this difliculty.

Diazotype light-sensitive materials disclosed in British Pat. 867,630 and Japanese patent publication 6,233/ 1961, include highly sensitive diazonium compounds having the following general formula:

in which X is an acid anion, Y is a fluorine or chlorine atom, R and R are chosen from alkyl, hydroxyalkyl and chloralkyl groups having at most 4 carbon atoms and aralkyl groups and nuclear substituted chloroaralkyl groups having at most 11 carbon atoms, R, is chosen from alkyl groups having at most 4 carbon atoms and aralkyl groups having at most 11 carbon atoms, and R R and R contain together at least 6 and at most 17 carbon atoms.

In the above-mentioned diazotype light-sensitive material, organic acids such as citric acid or tartaric acid or inorganic acids such as boric acid or sulfuric acid are often used as acid stabilizers. The foregoing diazonium compounds decompose at temperatures as low as 80 C. to 100 C. They decompose slowly during the summer even when they are stabilized by acid. This causes an autocoupling with the decomposition products which is manifested by the fogging of the light-sensitive material. Consequently, light-sensitive material containing highly sensitive diazonium compounds such as those mentioned above cannot be preserved for a long time and have a relatively short shelf life.

Various proposals have been made to eliminate this defeet. For example, in Japanese patent publication 17,238/ 1963, the use of salts of alkali metals of naphthalene mono-, -dior -tri-sulf0nic acid as stabilizers is suggested.

3,728,122 Patented Apr. 17, 1973 This solution to the problem has not proved to be satisfactory since these salts and the above mentioned diazonium compounds interact and coagulate to form a tar-like material.

In order to diminish this coagulation and the formation of the tar-like products, it has been proposed to form a precoat layer containing such stabilizers, together with starch or silica on a support, and then to apply an aqueous light-sensitive solution containing the diazonium compound to the precoat layer. Even when this method is used, however, the stabilizer dissolves into the light-sensitive solution being applied to the substrate and reacts with the diazonium compound to form the tar-like products. A light-sensitive material prepared under such conditions cannot yield a good dye-image With a clear background and does not have good stability.

It is, therefore, an object of the present invention to alleviate the above-mentioned disadvantage and to provide a stable one-component diazotype light-sensitive material.

THE INVENTION The present invention relates to a one-component diazotype light-sensitive material having high prcservability which contains a condensation product made from naphthalenesulfonate or alkylnaphthalenesulfonate and formaldehyde in a precoat layer on a surface of a supporting sheet.

The condensation products used in this invention have. the following general formula:

$0 K $01K S OaX wherein R R and R are hydrogen or alkyl containing from about 1 to 5 carbon atoms, X is sodium or potassium, and n is from about 0 to 8.

These condensation products are known as anion surface active agents. It has now been discovered that they are effective to improve the stability of diazonium compounds. Since these stabilizing agents have sulfonic acid groups which would interact with the diazonium compounds, they cannot be used by dissolving them together with the diazonium compound in a light-sensitive solution. Satisfactory results can be obtained however by using them dispersed in a precoat layer comprising starch, powdered silica, polyvinyl acetate or like excipients.

A typicalj'precoat composition for forming the precoat layer would contain, for example, 100 g. of fine powdered cornstarch, 20 g. of fine powdered silica and g. of polyvinyl acetate emulsion having a 50% solids content in 1000 cc. ofwater, together with 1 g. to 10 g. of the stabilizer. f

The compositions most useful in the practice of this invention are those in which the amount of stabilizer used is from about 0.1 to 1.0 gram per gram of diazonium compound. The composition may be spread on the support sheet by any convenient method, for example, roller coating. As spread it will normally be of a thickness such that the coat will contain from about 0.01 to 0.15 gram of stabilizer per square meter of support sheet. Appreciable variations from these ranges can be tolerated while still obtaining useful results.

The preparation of the condensation products utilized in this invention follows standard procedures. It is normally not practical to prepare and isolate pure compounds. Fortunately, it is not necessary to use pure compounds in the practice of the invention. The mixtures obtained by the usual synthetic techniques can be employed. Those products in which the mean value of n is from about (G) to 8 are preferably used. 0 H C H C H c H Typical stabilizing condensation products which may a 7 a 7) 4 n I be used in the practice of this invention include the fol- CH? CH lowing in which n has the same meaning as above. (l) Condensation product made from sodium naphthalenesulfonate and formaldehyde:

S OaNa S OsNa n S OsNa A Gib- CHI-1 CaHr F (|J4Hg(0r CaH7) 04H; SO|Na some n S 01Na 0 (2) Condensation product (Compound B) made from sodium methylnaphthalenesulfonate and formaldehyde; A A

O Na n OsNB OzNa CH3 Similar products are obtained from other naphthalene- CH: CH: l 1 CH: CH: sulfonates in which the sodium is replaced with potassium and the alkyl group is on a portion other than the 4- position on the naphthalene nucleus. g I I The following non-limiting examples are given by way O Na S O=Na SOZNB of illustration only.

EXAMPLE 1 (3) Condensation product (Compound C) made from sodium propylnaphthalenesulfonate and formaldehyde;

A precoat mixture was prepared from the following 1C) ingredients:

:111 Es l 0:131

Water cc.... 1000 CH2 CH2 Cornstarch (particle size: l-S g-.. 100 Powdered silica (particle size; 15,u) g-.. 20 Polyvinyl acetate emulsion (solid: 50%) g 95 to 0 m n c mp n A; "-24 g 3 (4) Condensation product (Compound D) made from sodium butylnaphthalenesulfonate and formaldehyde; A hght'sensmve solution (a solution for forming a 40 light-sensitive layer) was prepared from the following (D) ingredients:

4 a $4H0 "I C|Hr CH2 CH2 Water CC Tartaric acid r! 10 Concentrated sulfuric acid cc 4 2 phenoxy 5 chloro 4 dibenzylaminobenzene OM l l diazonium chloride VzZnCl g 9.5 Methylene blue g 0.1 (5) Condensation product (Compound E) made from Saponin g 1 sodium amylnaphthalenesulfonate and formaldehyde;

(E) The precoat composition was applied to a surface of a 04H supporting sheet and dried off and then the light-sensitive l l E solution was applied to the surface and dried otf to pro- 0 55 vide a one-component diazotype light-sensitive material 7 (Sample A). Another light-sensitive material (Sample B) for comparative test was obtained by repeating the same I procedure except that the precoat composition did not some. SOaNa n 031%. contain Compound A. Sample A and Sample B were prepared by subjecting Samples A and B to artificial aging cfllldellsatlon lll'odlwt (CQmPOlmd made from by keeping them in a desiccator at a temperature of 50 dillm naphihaleneslllfonate, Sodium butylnaphthalfine" C. and a relative humidity (RH) of 50% for 48 hours. sulfonate and formaldehyde: The comparative test of Samples A, A, B and B was carried out as follows: (F) 6 A black dye-image was formed on each sample by over- I' (34mm H) l laying an image-carrying original on each sample, exposing it to light and then developing it in the following fig fig fi liquid developer:

I Water cc 1000 Lo n, soaNa n SOaNis rThiourca 10 Phloroglucin g (7) Condensation product (Compou ds G a H) made Citric acid g from sodium propylnaphthalenesulfonate, Sodium butyl- Sodium citrate g '80 naphthalenesulfonate and formaldehyde; Sodium benzoate V ,s g

Densities of the dye-images and the backgrounds (nonimage area of the sample) were measured to compare and the following results were obtained.

The density was measured with a Photovolt densitometer, sold by Photovolt Co., using a green filter.

From these results, the advantageous stabilizing action effect of the condensation product made from sodium naphthalenesulfonate and formaldehyde can be detected.

EXAMPLE 2 One-component diazotype light-sensitive materials were obtained by repeating the same procedure as that of Example 1 except that the aforementioned Compound F (n-2) was employed instead of Compound A in the precoat solution and the comparative test was carried out in the same manner as that of Example 1. The results thus obtained were similar to that of Example 1.

Compound F (n-2) used in this example was made as follows:

Butylnaphthalenesulfonic acid was obtained by the condensation of 30 cc. of butyl alcohol and 80 g. of naphthalene in the presence of 35 cc. of concentrated sulfuric acid. 30 g. of butylnaphthalenesulfonic acid and 5 g. of powdered naphthalene were mixed in a mixture of 40 g. of concentrated sulfuric acid and cc. of water, and then 11 cc. of 30% aqueous solution of formaldehyde were added to the mixture under stirring at a temperature between 50 C. and 60 C. and the stirring was continued at this temperature for 3.5 hours to separate the reaction product as a viscous mass. The desired condensation product, Compound F (18 g.) was obtained by the neutralization of this viscous mass with sodium hydroxide.

EXAMPLE 3 One-component diazotype light-sensitive materials were obtained by repeating the same procedure as that of Example 1 except that the aforementioned Compound D (n-l.4) was employed instead of Compound A in the precoat solution, and the comparative test was carried out in the same manner as that of Example 1. The results thus obtained were similar to that of Example 1.

Compound D (n-1.4) used in this example was made as follows:

After 6 g. of powdered naphthalene were added to dibutyl sulfate made from 25 cc. of concentrated sulfuric acid and 7 cc. of n-butyl alcohol, this mixture was stirred for a while at a temperature of 50 C. As cooled, the mixture separated into two layers. The lower layer was removed and 5 cc. of 30% aqueous solution of formaldehyde were added to the upper layer (butylnaphthalenesulfonic acid) under stirring at a temperature of 50 C. and the stirring was continued at a temperature between 50 C. and 60 C. until the reaction was complete, as indicated by the disappearance of formaldehyde. After cooling, the mixture separated into two (upper and lower) layers. The desired condensation product, Compound D (4.5 -g.), was obtained by the neutralization of the reaction product of the upper layer with sodium hydroxide.

6 EXAMPLE 4 A precoat composition was prepared from the following ingredients:

Water cc 1000 Colloidal silica g 20 Polyvinyl acetate emulsion (solid: 50%) g 40 Compound D (n--1.4) g 5 A light-sensitive solution was prepared from the following ingredients:

Water cc 1000 Tartaric acid g 10 Concentrated sulfuric acid cc.... 4 2 methoxy 5 chloro-4-methylbenzylaminobenzene diazonium chloride /zZnCl;; g 10 Methylene blue g 0.1 Saponin g 1 Liquid developer:

Water cc 1000 Thiourea g 15 Phloroglucin g 4 Benzoic acid g-.. 25 Sodium benzoate g 15 Sodium formate g 150 Sample A gave a clear, black dye-image having good intensity on the vivid background, while Sample B gave an unclear dye-image of very low density.

EXAMPLE 5 One-component diazotype light-sensitive materials were obtained by repeating the same procedure as that of Example 4 except that 4 g. of the aforementioned Compound G (nz5) was employed instead of 5 g. of Compound D (n-1.4) in the precoat solution, and the comparative test was carried out in the same manner as that of Example 4. The results thus obtained were similar to that of Example 4.

Compound G (1W5) used in this example was made as follows:

Butylnaphthalenesulfonic acid was obtained by the condensation of 12 cc. of butyl alcohol and 15 g. of naphthalene in 20 cc. of concentrated sulfuric acid, and propylnaphthalenesulfonic acid was obtained by the condensation of 25 cc. of propyl alcohol and 30 g. of naphthalene in 37 cc. ofconcentrated sulfuric acid. 32 g. of butylnaphthalenesulfonic acid and 30 g. of propylnaphthalenesulfonic acid were mixed in 70 cc. of concentrated sulfuric acid, and then 11 cc. of 30% aqueous solution of formaldehyde were added to the mixture under stirring at a temperature between 50 C. and 60 C. and the stirring was continued for about 8 hours while slowly raising the temperature to C. at last. As allowed to stand, the mixture separated into two layers. The desired Compound G (19 g.) was obtained by the neutralization of the reaction product of the upper layer with sodium hydroxide.

What is claimed is: I

1. One-component diazotype light-sensitive material comprising a precoat layer between a supporting sheet and a light-sensitive layer containing a diazonium compound, the precoat layer containing from about 0.01 to 0.15 gram per square meter of support sheet of a stabiliz- 3 ing compound having the following formula dispersed in 5. A light-sensitive material as in claim 1 wherein the an excipient: stabilizing compound is represented by the formula:

IEIh R1 R1 (IJaH1 (LHKOX' C3111) C4H9 1 CH; CH: CHEN CH: oax so): it SOzX EiO=Na SOQNB n SO Na Wherem p References Cited R1, R2 and R3 are hydrogen O1 containing from about 1 to 5 carbon atoms, X is sodium or potassium, and 3,102,812 9/1963 Welch 96-91 R n is an integer from about 0 to 8. v 2,498,722 2/1950 Straley 96-91 R 2. A light-sensitive material as in claim 1 wherein the i i g g stabilizing compound is represented by the formula: 1m 0W5 et a 6 1 i 2,541,727 2/1951 Von Glahn et al. 96-91 R 2 545 423 3/1951 Duerr 9691 R 011- CH 2,593,911 4/1952 Neumann et al. 96-91 R p FOREIGN PATENTS $0M $0M 571,302 9/1945 Great Britain 96-91 R 3. A light-sensitive material as in claim 1 wherein the I a 609,912 3/1962 Belgium 9649 stabilizing compound is represented by the formula:

0411mm (34H. OTHER REFERENCES I OH CH Dinaburg, M. S., Photosensitive Diazo Compounds,

" The Focal Press, 1964, p. 93 relied on.

Muller, P., Precoat of Diazotype Paper, Tappi, Au-

gust 1965, pp. SSA-59A. i V I SoNa 03m CHARLES L. BOWERS, JR., Primary Examiner 4. A light-sensitive material as in claim I wherein the stabilizing compound is represented by the formula: 35 US. Cl. X.R.

I- 04H 96-49, 91 R on, on?

I i 1 SOrNa SO1Na n SOzNa. 

